mecab-python3

library1.0.12pypypi✓ verified 22d ago

mecab-python3 is a Python wrapper for the MeCab morphological analyzer, primarily used for Japanese text. It provides an interface to MeCab's tokenization and part-of-speech tagging functionalities. The library currently supports Python 3.8 and greater, with releases often driven by new Python version compatibility and critical bug fixes.

ai-ml data

pip install mecab-python3

github ↗package ↗

INSTALL

IMPORT

SIG · MECAB-PYTHON3

mecab-python3

ai-mlpythonv1.0.12

Install

7.7s avg

Import

—

Disk

477MB

Pass rate

5/ 10

Env Coverage5 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v1.0.12 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

glibc

py 3.10

1/3 runs

✓ 7.33s

py 3.11

1/3 runs

✓ 7.33s

py 3.12

1/3 runs

✓ 8s

py 3.13

1/3 runs

✓ 7.9s

py 3.9

1/3 runs

✓ 8s

477MB installed

● package 477MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

MeCab

✓ import MeCab

✗ import mecab

The module name is capitalized 'MeCab', not 'mecab'. Common ImportError due to incorrect capitalization.

This quickstart demonstrates basic morphological analysis using MeCab, including word segmentation ('wakati-gaki') and detailed analysis. It highlights the necessity of a dictionary for operation and includes basic error handling for common setup issues.

import MeCab import os # The library needs a dictionary to function. unidic-lite is recommended. # Ensure it's installed: pip install unidic-lite try: # Initialize Tagger for 'wakati-gaki' (word segmentation) wakati = MeCab.Tagger('-Owakati') text_wakati = wakati.parse('すもももももももものうち') print(f"Wakati-gaki: {text_wakati.strip().split()}") # Initialize Tagger for detailed analysis (default) tagger = MeCab.Tagger('') # An empty string often defaults to system mecabrc or attempts autodetection text_full = tagger.parse('これは日本語の形態素解析のテストです。') print(f"\nDetailed Analysis:\n{text_full}") except RuntimeError as e: print(f"MeCab initialization failed: {e}") print("Please ensure a dictionary (e.g., unidic-lite) is installed and correctly configured.") print("On Windows, you may also need the Microsoft Visual C++ Redistributable.") except ImportError as e: print(f"Missing dictionary package: {e}") print("Please install a dictionary, e.g., 'pip install unidic-lite'")

Debug

Known issues

breakingPython 2 support was officially dropped in version 1.0.3. Users on Python 2 must use an older version.

fix

Upgrade to Python 3.x and mecab-python3 version 1.0.3 or higher.

affects: < 1.0.3

breakingThe bundled IPAdic dictionary was removed in version 1.0.0 (first released as 1.0.0a1). This means MeCab will now rely on system-installed dictionaries or those installed via Python packages like `unidic-lite`.

fix

Explicitly install a dictionary package like `unidic-lite` (`pip install unidic-lite`) or ensure a system-wide MeCab dictionary is available and configured.

affects: >= 1.0.0

gotchaMeCab requires a dictionary to perform analysis. While `mecab-python3` installs the Python wrapper, a dictionary like `unidic-lite` or `unidic` must be installed separately (e.g., `pip install unidic-lite`) or by using the `mecab-python3[unidic-lite]` extra. Without a dictionary, `MeCab.Tagger()` will fail with a `RuntimeError`.

fix

Install a dictionary package: `pip install unidic-lite`. If specifying a custom dictionary path, ensure a valid `mecabrc` file is also present.

affects: All versions

gotchaOn Windows, a Microsoft Visual C++ Redistributable is required for `mecab-python3` wheels to function correctly. This is a common oversight leading to runtime errors.

fix

Download and install the appropriate Microsoft Visual C++ Redistributable for your system (e.g., from Microsoft's website).

affects: All versions on Windows

gotchaSince version 1.0.4, errors during MeCab initialization (e.g., missing dictionary) now consistently throw a `RuntimeError` instead of printing messages directly to `stdout`. This is an improvement but could affect scripts that parsed `stdout` for error detection.

fix

Update error handling logic to catch `RuntimeError` for initialization failures. The error message provides guidance.

affects: >= 1.0.4

gotchaThe `MeCab.VERSION` attribute (if accessed) refers to the version of the underlying MeCab C++ library (typically 0.996), not the `mecab-python3` Python package version. It has not changed for many years and is not generally useful for tracking the Python wrapper's version.

fix

Refer to `mecab-python3.__version__` or PyPI for the Python package version. Avoid relying on `MeCab.VERSION`.

affects: All versions

Errors

Common errors & fixes

ImportError: DLL load failed while importing _MeCab: The specified module could not be found.

This error typically occurs on Windows when the necessary Microsoft Visual C++ Redistributable is not installed, or there's an issue with how the underlying MeCab C++ library is linked.

fix

Install the appropriate Microsoft Visual C++ Redistributable for your system (e.g., from Microsoft's website). On Windows, installing `mecab-python3` within a virtual environment is also a recommended solution.

RuntimeError: Failed when trying to initialize MeCab.

This generic runtime error often indicates that the `mecab-python3` library cannot find an installed MeCab dictionary, which is essential for its operation.

fix

Install a MeCab dictionary, such as `unidic-lite`, using pip: `pip install unidic-lite`. If you have a specific dictionary, you might need to provide its path when initializing `MeCab.Tagger()`.

UnicodeDecodeError: 'utf-8' codec can't decode byte 0x... in position ...: invalid start byte

This happens when MeCab processes text with an encoding different from the expected 'utf-8', or due to potential memory management issues within MeCab itself, especially with older versions.

fix

A common workaround is to call `tagger.parse('')` with an empty string once before processing actual text. Ensure your input text is consistently UTF-8. If the problem persists, try building and installing MeCab from its latest source and then reinstalling `mecab-python3`.

ModuleNotFoundError: No module named 'mecab'

This error occurs when the `mecab-python3` library is imported using incorrect capitalization in the `import` statement.

fix

Correct the import statement to use `MeCab` with a capital 'M': `import MeCab`.

Upgrade

Version history

1.0.12latest on PyPI · released Nov 25, 2025

Audit

Dependencies

unidic-liteoptionalA dictionary is essential for MeCab to function; unidic-lite is recommended for its small size and active maintenance. Other dictionaries can be used but require manual configuration.

Microsoft Visual C++ RedistributableoptionalRequired for binary wheels to work on Windows systems.

Agent activity

58 hits · last 30 days

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Bingbot

Resources

githubhttps://github.com/SamuraiT/mecab-python3 ↗

packagehttps://pypi.org/project/mecab-python3/ ↗